Agonising decisions have been part of Greek culture since Atropos, one of the three mythological Fates, began pondering how to cut the thread of life and send people to their deaths. On Sunday, Greeks will go to the polls knowing their choices could slice Greece's ties with its lenders and propel the country to its economic demise.

For some the choice on 17 June is a simple one: tough it out in the euro and wait for the economy to recover or risk it all on a potentially disastrous return to the drachma. But even with public coffers due to empty by mid-July unless cash is injected from a new loan instalment, many Greeks refuse to see Sunday's vote this way. An opinion poll for Kathimerini newspaper suggested that one in two Greeks want the euro but also reject the austerity the eurozone and IMF are demanding.

This appears to be the big contradiction at the heart of these elections but the incongruity has more to do with the tumultuous transition Greece is going through than a lack of awareness about the sacrifices or changes needed to survive this crisis. Greece is at a point in its history where its economic, social and political models are broken. The debt crisis that erupted in 2009 exposed the decrepit state of the country's structures. A fiscal adjustment programme that was poorly communicated and implemented at a national and European level put paid to hopes of renewal.

Under the guardianship of the EU and IMF, a government led by the centre-left Pasok and then a coalition administration that included the centre-right New Democracy wilfully ignored most opportunities to conduct vital structural reforms, such as the overhaul of a woefully inefficient public administration. These two parties also passed up chances to rein in public spending and slash waste, relying instead on repeated tax hikes to bring down the public deficit. For an economy already in recession from 2008, this proved a lethal combination. Greece's economic downturn has already lasted longer than the Great Depression. Unemployment, currently at 22%, is set to overtake the peak of 25% in the US in 1933.

As they sink into this economic morass, Greeks are being advised to make sure New Democracy, which wants to renegotiate the loan terms, beats leftist Syriza, which intends to discard the austerity measures. This would allow New Democracy and Pasok, likely to come a distant third, to form the basis of a new coalition government to keep Greece in the euro. But the idea of the responsible vote going to two parties that failed to show responsibility is also a contradiction.

New Democracy and Pasok have ruled Greece since 1974 and carry the largest share of blame for the country's failed economy and self-serving political system. Since the 1990s they've promised reforms to make Greece's economy more competitive and its society fairer but have largely failed to deliver. During this crisis they displayed fear of upsetting their strongholds in the public sector and cosy relationships with numerous private sector groups . So, logic would dictate that if Greeks are genuinely in favour of reform – and opinion polls have consistently shown wide support for many of the structural changes needed – they would be foolish to give these two parties another chance.

The contradictions do not end there. In its bid to complete an unlikely ascent to power, Syriza hardly provides voters with a more reliable choice. At times it has obfuscated its message on the bailout but Syriza's most impressive sleight of hand has been its attempt to appeal to incompatible constituencies. In the inconclusive elections on 6 May, it was the most popular party among civil servants – the group that has probably benefited most from four decades of deeply flawed governance – but it also ranked first among Greece's unemployed and young people – the groups that have suffered most from the inefficiency and inequity this system bred. Syriza promises a new start but it also gives the impression that little will change in Greece's problematic public sector.

Some Greeks will agonise over these paradoxes right up to the last minute.

At the end of it all, though, there may be one contradiction they are unlikely to resolve. Regardless of who Greeks vote for on Sunday, the demands from the eurozone for an austerity programme that none of the parties believe in any more, at least in its current form, will remain. In 1981, Greece's partners allowed it to join what is today termed a "union" in the hope it would nurture a fledgling democracy deeply scarred by years of civil war, divisive politics and military rule. But from next week, Greece could find its democratic process counting for very little in its struggle to stay in a eurozone that is far from united. Atropos and her shears no longer reside in Greece; fate is now decided elsewhere.